1. Field of the Invention
This invention relates to a closing device for a switchgear cabinet door, machine casing, or the like, having a securing device, including a lock attached to the switchgear cabinet door, machine casing, or the like, with a first locking element, and a second locking element fastened on the door frame, machine casing frame, or the like, wherein both locking elements can be brought into functional contact with each other and again out of functional contact under the control of an electrical signal.
2. Description of Related Art
A closing device is used for security reasons wherever defined prerequisites for releasing the opening process of the switchgear cabinet door, or machine casing, or the like, must be observed, for example switching off the supply voltage, or the like.
Such a closing device is known from German Patent Reference DE 295 07 654 U1. Here, a so-called pivot lever closing device is employed, and locking takes place by the pivot lever, which must be placed into its initial position in a lock recess for this purpose. This results in a considerable intervention in the closing device, i.e. a considerable change of the lock mechanism.
It is one object of this invention to create a closing device of the type mentioned at the outset, which permits locking in the closed position in a considerably simpler way, and which can be applied to all customary types of locks.
In accordance with this invention, this object is attained using a lock with a locking mechanism, which can be placed in different directions of rotation. A locking member, which is subjected to spring tension, is displaceably guided. In one locking position the locking member under spring tension blocks the rotating movement of the lock mechanism, and a trigger member can be displaced by an electromagnet attached to the door frame or the machine casing frame, by which the locking member in the lock can be placed into an unlocking position which releases the rotating movement of the lock mechanism.
Conventional locks have a lock mechanism which can be placed into a rotating movement. The locking and unlocking of the lock can be controlled from the switchgear cabinet or the machine using an electrically controlled trigger member with the adjustable locking member in the lock and only needs to work together with the lock mechanism which can make rotating movements. This locking and unlocking mechanism can be applied to all types of locks without it being necessary to essentially change the actual locking mechanism.
The functional connection between the locking member and the trigger member can be achieved in a simple manner because on the side facing the door frame or the machine casing frame, the locking member is accessible through an opening in the lock housing and is adjustably guided in this opening. In the locked position a compression spring keeps the locking member, which has detents, in place in the opening.
In the closing device the locking member acts together with a cam disk of the locking mechanism, which has a flat place for supporting it on the locking member and for maintaining the locked position. Outside of the flat place the cam disk partially covers the opening and keeps the locking member in this position when the locking member is placed into the unlocked position in order to obtain the required functional connection between the locking element and the locking mechanism. Here, the lock mechanism includes a lock actuating element, a pinion for a pair of push rods for improving the locked position, the cam plate, and a turnbuckle, all of which are connected with each other, fixed against relative rotation. The turnbuckle participates in the locking process of the switchgear cabinet door or machine casing.
In accordance with one embodiment, for the displacement of the trigger member the electromagnet is attached to a bracket fastened on the door frame or the machine casing frame and controls a draw-in plate with a displacement rod. The displacement rod is conducted through openings of systematic rows of holes of the door frame or the machine casing frame. An end of the displacement rod projecting out of the door frame or the machine casing frame supports the trigger member. In this case the draw-in plate is guided, fixed against relative rotation, in openings of the door frame or the machine casing frame by guide bolts. This function also applies to the displacement rod with the trigger member, so that the trigger member can always act together in the same position with the locking member.
For one, the control of the locking and unlocking mechanism can be laid out in such a way that, when the electromagnet is excited, the trigger member brings the locking members of the lock into the unlocking position when the switchgear cabinet door or the machine casing is closed. After setting the lock into the locking position and with the electromagnet switched off, the compression spring in the lock puts the locking member into the locking position. In another embodiment when the electromagnet is not excited, a compression spring maintains the trigger member in the unlocking position. When closing the switchgear cabinet door or the machine casing, the locking member in the lock is maintained in the unlocked position, and after setting the lock into the lock position, with the electromagnet excited, the compression spring in the lock places the locking member into the locking position.